en_tn_condensed/1sa/15/11.md

It grieves me

"I am sorry"

he has turned back from following me

Saul not obeying Yahweh is spoken of as if Saul had physically turned away from walking behind God. Alternate translation: "he has stopped following me" (See: rc://en/ta/man/jit/figs-metaphor)

has not performed my commandments

"has not obeyed what I commanded him to do." Saul was to completely destroy everything and everyone. God had placed a ban on the Amalekites. But Saul permitted some livestock to live.

Samuel was angry

Possible meanings are 1) Samuel was angry with Saul for his disobedience or 2) Samuel was disturbed.